Smartphones keep getting faster, better and slicker. One part of the device that’s having trouble keeping up is the battery. Many state-of-the-art smartphones have trouble making it through a single day on a charge, much less two or three days like the simple Nokia phones of yore. But can anything be done about this, short of buying an extra battery? JuiceDefender for Android says the answer is yes.

Before we begin, one note. The link above leads to JuiceDefender’s beta version. LaterDroid, the developer, normally offers a free version on the Android Market. However, at the moment they’re having some trouble with the market, and have asked me to link to the Beta version instead. It’s free and quite stable.

When I started the app, the first thing I noticed was the unique look-and-feel of the interface:

Many say Android’s lack of UI guidelines is bad, but this is one app that uses its creative freedom to good effect. The interface blends copious amounts of explanations along with the buttons, in a way that feels natural and uncluttered. As you can see above, it starts off disabled by default, so tap that “enabled” button to get started.

What JuiceDefender essentially does is disable some of your device’s functions at times you’re not likely to notice, thus saving you some precious power. For instance, if you’re not connected to a WiFi network, JuiceDefender will simply disable your device’s WiFi radio. Once fifteen minutes elapse, JuiceDefender will enable the radio again, check for a connection, and if there’s still no connection, it will shut it off again. So you no longer have to remember to toggle WiFi off when you leave the house or the office.

Another example is turning off data during the night – from 2am till 6am (or at other hours you can configure), JuiceDefender can simply disable mobile data. After all, you’re not likely to be reading a lot of emails in your sleep (I hope).

Since there are so many options, JuiceDefender works using profiles. There are three main profiles offering varying degrees of aggressiveness (i.e, which services are shut down and when), plus two customization options (“customize” and “advanced”). Since I’m using the free version, not all profiles are available. However, the interface initially did not make it clear which profiles can be used and which are paid-version only.

For instance, I tapped the “aggressive” profile which should be available in the free version:

Then I tapped “extreme“, which should not be available in this version:

Can you tell the difference? I sure can’t. I figured this must be a bug, and restarted the app. Indeed, after a restart I got a different result when tapping “aggressive“:

This sure makes things clearer. I love the detailed explanation, and how it blends well into the interface. Now let’s tap “extreme” again:

Okay, this is certainly clearer. No “extreme” profile in the free version. Now let’s take a look at the “customize” option:

This opens up a whole new “Settings” tab, with numerous options. However, if you’re using the free version, I suggest you don’t even bother with this tab. Only “Mobile Data” and one other option are enabled. The rest are shown with complete explanations, but cannot be modified. This does, however, give a good sense of what the paid versions of the app (Plus and Ultimate) can do.

That’s right, JuiceDefender has not one, but two paid versions. Plus goes for €1.99 on the market, and allows you to access the Extreme profile, control mobile data and tweak a host of other settings. Ultimate will set you back €4.99 and unleash JuiceDefender’s full power, no holds barred. The app features a handy comparison chart so you can figure out which version to buy:

On its own, the free version of JuiceDefender can be a nice “set it and forget it” way to conserve battery use. You can use it to evaluate the app’s basic efficiency, see if it’s making a difference for your device and get used to the idea of conserving power via an app. But if you’re serious about improving battery life, you would definitely want to go for one of the paid versions.

Let us know what you think of JuiceDefender and if you know of any other alternatives we should be looking at.

You should also write about SuperPower. It's free and has more features (comparing to free version od JD). Unfortunately it is very rarely updated (last update was like 4 months ago?). Still it's good and i prefer it instead of JD.

I am so very close to hooking my ThunderBolt right in to the nearest trash can. I swore after purchasing my first Android when it first came out that I would move on to an iPhone, I couldn't do it and moved to Thunderbolt and MAN do I hate it.

Hopefully this works because I truly have to charge the thing 3x a day, or should I just call it life support.